diff --git a/ChangeLog b/ChangeLog
index bb73136c1263e2666d6af4cc7f193c657541e848..95d4b9f6338c47bf133d13da86550d6710da5acf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -590,4 +590,5 @@
0.3.20 2008-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
* Initial release of a tiny windowing system for NuttX (not well tested at initial check-in)
+ * Add fixed precision sin() and cos() (not well tested at initial check-in)
diff --git a/Documentation/NuttX.html b/Documentation/NuttX.html
index 0fdedd3db1afa27a051b68c615f5ff3741f91c47..6dcce8b587d8e2da649e4b8d210eb0af1f5893aa 100644
--- a/Documentation/NuttX.html
+++ b/Documentation/NuttX.html
@@ -1206,6 +1206,7 @@ buildroot-0.1.2 2007-11-06 <spudmonkey@racsa.co.cr>
<pre><ul>
nuttx-0.3.20 2008-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
* Initial release of a tiny windowing system for NuttX (not well tested at initial check-in)
+ * Add fixed precision sin() and cos() (not well tested at initial check-in)
pascal-0.1.3 2008-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
diff --git a/include/fixedmath.h b/include/fixedmath.h
index 3f9e8e0e613be2ea5059b1b975277d02f7e75107..1c42537547a1a2aadf18e72c3eadd64bdab23bf0 100644
--- a/include/fixedmath.h
+++ b/include/fixedmath.h
@@ -54,6 +54,9 @@
#define b8HALF 0x0080 /* 0.5 */
#define b8ONETENTH 0x001a /* 0.1 (acutally 0.1015625) */
#define b8ONEHUNDRTH 0x0003 /* 0.01 (actualy 0.0117198765) */
+#define b8HALFPI 0x0192 /* 1.5703125 */
+#define b8PI 0x0324 /* 3.1406250 */
+#define b8TWOPI 0x0648 /* 6.2812500 */
#define b8MAX 0x7fff /* Max value of b8_t */
#define ub8MAX 0xffff /* Max value of rb8_t */
@@ -68,6 +71,9 @@
#define b16ONETENTH 0x0000199a /* 0.1 (actually 0.100006..) */
#define b16ONEHUNDRTH 0x0000028f /* 0.01 (actually 0.0099945..) */
#define b16ONETHOUSTH 0x00000042 /* 0.001 (actually 0.000100708..)*/
+#define b16HALFPI 0x0001921f /* 1.57078552246 */
+#define b16PI 0x0003243f /* 3.14158630371 */
+#define b16TWOPI 0x0006487b /* 6.28312683105 */
#define b16MAX 0x7fffffff /* Max value of b16_t */
#define ub16MAX 0xffffffff /* Max value of ub16_t */
@@ -84,6 +90,9 @@
#define b32ONEHUNDRTH 0x00000000028f5c29 /* 0.01 */
#define b32ONETHOUSTH 0x0000000000418937 /* 0.001 */
#define b32ONETENTHOU 0x0000000000068db9 /* 0.0001 */
+#define b32HALFPI 0x00000001921eb9ff /* 1.57078134990 */
+#define b32PI 0x00000003243f6b4f /* 3.14159269980 */
+#define b32TWOPI 0x00000006487ae7fd /* 6.28312539984 */
#define b32MAX 0x7fffffffffffffff /* Max value of b16_t */
#define ub32MAX 0xffffffffffffffff /* Max value of ub16_t */
@@ -131,6 +140,8 @@
#define b8mulb8(a,b) b16tob8((b16_t)(a)*(b16_t)(b) /* Muliplication */
#define ub8mulub8(a,b) ub16toub8((ub16_t)(a)*(ub16_t)(b) /* Muliplication */
#define b8muli(a,i) ((a)*(i)) /* Simple multiplication by integer */
+#define b8sqr(a) b8mulb8(a,a) /* Square */
+#define ub8sqr(a) ub8mulub8(a,a) /* Square */
#define b8divb8(a,b) b8tob16(a)/(b16_t)(b) /* Division */
#define ub8divub8(a,b) ub8toub16(a)/(ub16_t)(b) /* Division */
#define b8divi(a,i) ((a)/(i)) /* Simple division by integer */
@@ -162,9 +173,11 @@
#define b16idiv(i,j) (((i)<<16)/j) /* Division of integer, b16 result */
#ifdef CONFIG_HAVE_LONG_LONG
-# define b16mulb16(a,b) b32tob16((b32_t)(a)*(b32_t)(b) /* Muliplication */
+# define b16mulb16(a,b) b32tob16((b32_t)(a)*(b32_t)(b)) /* Muliplication */
# define ub16mulub16(a,b) ub32toub16((ub32_t)(a)*(ub32_t)(b)
-# define b16divb16(a,b) b16tob32(a)/(b32_t)(b) /* Division */
+# define b16sqr(a) b16mulb16(a,a) /* Square */
+# define ub16sqr(a) ub16mulub16(a,a) /* Square */
+# define b16divb16(a,b) b16tob32(a)/(b32_t)(b) /* Division */
# define ub16divub16(a,b) ub16toub32(a)/(ub32_t)(b)
#endif
@@ -196,10 +209,15 @@ extern "C" {
#ifndef CONFIG_HAVE_LONG_LONG
EXTERN b16_t b16mulb16(b16_t m1, b16_t m2);
EXTERN ub16_t ub16mulub16(ub16_t m1, ub16_t m2);
+EXTERN b16_t b16sqr(b16_t a);
+EXTERN ub16_t ub16sqr(ub16_t a);
EXTERN b16_t b16divb16(b16_t num, b16_t denom);
EXTERN ub16_t ub16divub16(ub16_t num, ub16_t denom);
#endif
+EXTERN b16_t b16sin(b16_t rad);
+EXTERN b16_t b16cos(b16_t rad);
+
#undef EXTERN
#if defined(__cplusplus)
}
diff --git a/lib/Makefile b/lib/Makefile
index c58b2dbcb666c5118c56f8bb19abe1f7a2ea38ef..47c410309c62e73d932e4e99cd752716ad07412e 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -71,7 +71,7 @@ endif
STDLIB_SRCS = lib_rand.c
-MATH_SRCS = lib_rint.c lib_fixedmath.c
+MATH_SRCS = lib_rint.c lib_fixedmath.c lib_b16sin.c lib_b16cos.c
UNISTD_SRCS = lib_getopt.c
ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
diff --git a/lib/lib_b16cos.c b/lib/lib_b16cos.c
new file mode 100644
index 0000000000000000000000000000000000000000..93f5ee2f691dd27daab3cac5ba8dd2f613fb783b
--- /dev/null
+++ b/lib/lib_b16cos.c
@@ -0,0 +1,64 @@
+/****************************************************************************
+ * lib/lib_b16cos.c
+ *
+ * Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
+ * Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ * used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <fixedmath.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: b16cos
+ ****************************************************************************/
+
+b16_t b16cos(b16_t rad)
+{
+ /* Compute cosine: sin(rad + PI/2) = cos(rad) */
+
+ rad += b16HALFPI;
+ if (rad > b16PI)
+ {
+ rad -= b16TWOPI;
+ }
+ return b16sin(rad);
+}
diff --git a/lib/lib_b16sin.c b/lib/lib_b16sin.c
new file mode 100644
index 0000000000000000000000000000000000000000..7e2bcac56fd8570ec0088f3fae2a2f70c27f3f2d
--- /dev/null
+++ b/lib/lib_b16sin.c
@@ -0,0 +1,110 @@
+/****************************************************************************
+ * lib/lib_b16sin.c
+ *
+ * Copyright (C) 2008 Gregory Nutt. All rights reserved.
+ * Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ * used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <fixedmath.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define b16_P225 0x0000399a
+#define b16_P405284735 0x000067c1
+#define b16_1P27323954 0x000145f3
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: b16sin
+ * Ref: http://lab.polygonal.de/2007/07/18/fast-and-accurate-sinecosine-approximation/
+ ****************************************************************************/
+
+b16_t b16sin(b16_t rad)
+{
+ b16_t tmp1;
+ b16_t tmp2;
+ b16_t tmp3;
+
+ /* Force angle into the good range */
+
+ if (rad < -b16PI)
+ {
+ rad += b16TWOPI;
+ }
+ else if (rad > b16PI)
+ {
+ rad -= b16TWOPI;
+ }
+
+ /* tmp1 = 1.27323954 * rad
+ * tmp2 = .405284735 * rad * rad
+ */
+
+
+ tmp1 = b16mulb16(b16_1P27323954, rad);
+ tmp2 = b16mulb16(b16_P405284735, b16sqr(rad));
+
+ if (rad < 0)
+ {
+ /* tmp3 = 1.27323954 * rad + .405284735 * rad * rad */
+
+ tmp3 = tmp1 + tmp2;
+ }
+ else
+ {
+ /* tmp3 = 1.27323954 * rad - 0.405284735 * rad * rad */
+
+ tmp3 = tmp1 - tmp2;
+ }
+
+ /* tmp1 = tmp3*tmp3 */
+
+ tmp1 = b16sqr(tmp3);
+ if (tmp3 < 0)
+ {
+ /* tmp1 = tmp3 * -tmp3 */
+
+ tmp1 = -tmp1;
+ }
+
+ /* Return sin = .225 * (tmp3 * (+/-tmp3) - tmp3) + tmp3 */
+
+ return b16mulb16(b16_P225, (tmp1 - tmp3)) + tmp3;
+}
diff --git a/lib/lib_fixedmath.c b/lib/lib_fixedmath.c
index 0b09653c561c0e35707c819f6e0e169dbd785829..e5f7ce3a482c31354735724db6853a9ee9085a9b 100644
--- a/lib/lib_fixedmath.c
+++ b/lib/lib_fixedmath.c
@@ -161,6 +161,53 @@ ub16_t ub16mulub16(ub16_t m1, ub16_t m2)
return (m1i*m2i << 16) + m1i*m2f + m2i*m1f + (((m1f*m2f) + b16HALF) >> 16);
}
+/****************************************************************************
+ * Name: b16divb16
+ **************************************************************************/
+
+b16_t b16sqr(b16_t a)
+{
+ b16_t sq;
+
+ /* The result is always positive. Just take the absolute value */
+
+ if (a < 0)
+ {
+ a = -a;
+ }
+
+ /* Overflow occurred if the result is negative */
+
+ sq = (bt_t)ub16sqr(a);
+ if (sq < 0)
+ {
+ sq = b16MAX;
+ }
+ return sq;
+}
+
+/****************************************************************************
+ * Name: b16divb16
+ **************************************************************************/
+
+ub16_t ub16sqr(ub16_t a)
+{
+ /* Let:
+ *
+ * m = mi*2**16 + mf (b16)
+ *
+ * Then:
+ *
+ * m*m = (mi*mi)*2**32 + 2*(m1*m2)*2**16 + mf*mf (b32)
+ * = (mi*mi)*2**16 + 2*(mi*mf) + mf*mf*2**-16 (b16)
+ */
+
+ uint32 mi = ((uint32)m1 >> 16);
+ uint32 mf = ((uint32)m1 & 0x0000ffff);
+
+ return (mi*mi << 16) + (mi*mf << 1) (((mf*mf) + b16HALF) >> 16);
+}
+
/****************************************************************************
* Name: b16divb16
**************************************************************************/